The Performance and Feasibility of Solar-Powered Desalination for Brackish Groundwater in Egypt

No

Reviewer Comment

Author Response

1

Minor English language editing required

Done

2

In Table (1), the Water Resources Deficit for Water Resources (BMC) - 2022 is incorrectly calculated, please correct this.

Done

3

In Table 1, what is meant by BMC in Water Resources (BMC) - 2022 and how does this differ from the BCM mentioned in the main text?

Billion Cubic Meters (BCM). All units are unified.

4

In Figure 13, the horizontal coordinate appears in Chinese, please correct it.

It is in English (Date)

5

Please explain what H_col stands for in equation (6).

average incident daily solar radiation

No

Reviewer Comment

Author Response

1

Introduction: The introduction section currently lacks a detailed overview of existing methodologies and their limitations in the field. Given the rapid advancement of this area, there is a need to incorporate recent statistics and references to provide a comprehensive and current context for the study.

I did incorporate the most recent water and desalination statistics and references to provide a comprehensive and current context for the study.

2

Data and References: The use of the year 2021 in lines 84 and 92, and in Table 2, suggests a need for data updating. It is recommended to either provide the most recent data or rephrase the text to accurately reflect the time-based situation of the data presented. Additionally, in Table 3 caption, a minor typographical error should be corrected by changing 'C◦' to '°C' for standardization.

·     2021 is the most updated published official figures on desalination.

·     The text is accurately reflecting the time-based situation of the data presented.

·     In Table 3 caption, a minor typographical error corrected by changing 'C◦' to '°C' for standardization (Done)

3

Results and Discussion: The paper needs an expanded analysis. This should include a comparative study of the solar-powered RO systems in relation to other desalination technologies and energy sources, providing a clearer understanding of the limitations of the technology under discussion.

In Egypt, other desalination technologies such as thermal technologies are not feasible and not efficient. The global trend is towards using RO. So, in this study we focus on the analysis of the RO pilot project results.

4

Figures and Tables: Improvements are required in the presentation of figures and tables, particularly Figures 1, 13-19, and Tables. These improvements should focus on the size, content clarity (such as clear axis titles), and overall quality. In Figures 13-14 and 16-19, there is a need to fix the presentation issues on the x-axis. Fig15, needs legends and axis. Also, ensure to provide appropriate copyright permissions for any previously published figures.

Done for all figures.

All axis titles were added to all figures as recommended by the reviewer.

5

Formatting: The use of bold font in Section 3.2 should be corrected.  A consistent formatting style throughout the document is recommended.

A consistent formatting style throughout the document was done and it will be reviewed by the Journal editors.

6

Mathematical Representations: In Equations 1-5, the use of 'x' as a multiplication sign is confusing. It is advisable to use standard mathematical notation

I did use the Equation in Word as a standard mathematical notation. However, I will check with Journal Editor to use their standard format.

7

References: The references used in the paper appear to be outdated. Given the dynamic nature of the subject matter, it is crucial to review and include more recent literature to provide a relevant and comprehensive scale

I did my best to use the most updated references. The most available recent published papers and reports are from 2013-2023 which were already used.

No

Reviewer Comment

Author Response

1

Abstract, a large amount of Egyptian water resources and diluted water current data are cited in the abstract, but some data need to be verified, such as: 11-12 data, please check!

All data about the water resources and desalination were collected from the following official peer reviewed published reports:

·     Ministry of Water Resources and Irrigation (MWRI), 2023, Egyptian National Water Resources Plan, Cairo, Egypt, pp. 125

·     Dawoud M., 2019, Egypt’s Non-Conventional Water Resources: Desalination Sector Analysis and Proposed Development, African Development Bank Report, pp. 97.

2

The abbreviation form of proper nouns is not recommended in keywords

Done (RO as changes to Reverse Osmosis)

3

Introduction is all describing the current status of Egypt's water resources, and does not highlight the main purpose, methods and significance of this study. There is a lack of analysis of the domestic and foreign research status of the technical means used in this paper.

·     One paragraph was added on highlight the main purpose, methods and significance of this study.

·     Literature review to analysis of the domestic and foreign research status on the solar powered desalination in Egypt and other region was added.

4

Suggested additional specific weighting information for 2.3.

Done

5

Specifically explain the relationship between feedwater temperature, production rate and desalination rate in row 303.

Done. Item 3.1

6

In line307, The graph does not have units.

Done. Unites were added  

7

In Lines 310-318, it has different fonts and formatting than the above, and it is recommended that this be reviewed

It is reviewed and has the same font. However, it will be reedited by the Journal

8

In Lines 328，“rows of units of kwh/m3”, m³ units are not superscripted, it is recommended to review the whole text.

All unites were revised across the manuscript

9

In Lines 331，Suggest explaining why the energy consumption is trending upwards

Due to decrease in the efficiency of the RO vessel with time.

10

In Lines 339，Suggest explaining that as the system operates, 6.23 to 7.22, the system recovery rate increases?

As shown in Figure (19) The system recovery ratio decreases with time and not increase.

No

Reviewer Comment

Author Response

1

All abbreviations should be described at their first mention in the abstract

Done

2

Font size of Tables should be checked

Fonts were unified. However, it will be reedited by the Journal during the production of the manuscript.

3

Some figures should be enhanced (especially resolution and image quality)

Al figures are produced either using Excell or GIS and will be provided to the Journal with high resolution

4

The manuscript still needs some work on the formatting (e.g., sup/subscripts, words capitalizations, punctuation rules, unnecessary bold font, few grammatical mistakes, etc.).

Formatting and unifying the fonts were done. However, it will be reedited by the Journal during the production of the manuscript.

5

The introduction section lacks references at some essential aspects (e.g., Recent studies indicated that the Egyptian population will be about 130 million).

Done. References were cited in the text and added to references list when they are needed.

6

From the authors point of view, can the solar powered desalination really solve the anticipated water crisis in Egypt? Are there any alternatives? Will the current geopolitical/economic situation in the area affect the feasibility of applying such technologies. I believe discussing such aspects briefly shall enrich this work.

Solar-powered desalination has the potential to address water scarcity by harnessing renewable energy to power the desalination process (mainly RO systems). However, challenges such as high initial costs, maintenance requirements, and the intermittent nature of solar energy may impact its practicality on a large scale.

The geopolitical and economic context of the region is crucial to understanding the feasibility of implementing such technologies. Factors such as political stability, international cooperation, and economic resources can significantly influence the success of large-scale projects. The authors may examine how geopolitical tensions or economic constraints in the area could impact the adoption of solar-powered desalination and whether there are potential collaborations or conflicts that could affect its implementation.

No

Comment

Author Response

1

The authors are advised to respond clearly and positively to comments.

Thanks for all reviews and I did my best to respond clearly and positively to all reviewers’ comments.

2

Use the multiplication sign (×) instead of using 'x' (as the alphabet) in equations.

Done. I used the Equation format and multiplication sign (×) in all equations.

3

In all equations, proofread that superscripts are provided properly. The equations are not formatted properly, as stated before.

All equations were formatted as per the journal standers using Equation in Microsoft Word.

4

In Section 3.2, avoid using bold concepts in content writing.

Done.

5

In Figures 13-14 and 16-19, there is a need to address presentation issues on the x-axis. The comment was given in the first round but was not addressed.

In all these figures x-axis is representing the date, and it is clear. The y-axis was revised and updated in all figures.

6

Figure 19, do you mean recovery on the y-axis?

Yes. Revised.

7

Figure 11 is still unclear. Please also ensure the originality of this figure (if it's not taken from any other work).

Figure 11. Schematic diagram for the design of the solar powered RO desalination plant. It is original figure created by the authors.

8

Table 3 caption: A minor typographical error should be corrected by changing 'C◦' to '°C'. Although the authors stated they have fixed the error, the issue is still there, and the same problem can be seen in other parts of the manuscript.

Thanks, done. I did my best to check all typo errors.

9

Please properly proofread the manuscript and ensure it is error-free.

I did my best to proofread the manuscript and ensure it is error-free. I hope that is fine now. 

No

Comment

Author Response

1

It has been modified and improved according to the requirements, and has basically reached the requirements of the journal.

Thanks for all reviews. Additional minor revision was done in the attached manuscript based on comments received from Revier (2).

2

Please carefully review the professional vocabulary involved in the full text before publication.

I did my best in carefully review the professional vocabulary involved in the full text. I hope that is fine and satisfied now.